Editor's Note: This article is adapted from Chapter 29 of Michael Otey's book ADO.NET: The Complete Reference (Osborne/McGraw-Hill, 2003)

SQL Server's IDENTITY columns let SQL Server automatically assign unique values to table rows. When you add a row to a table, the application you're using doesn't need to know anything about the row's unique identity number; SQL Server just handles that part automatically. However, in some cases, the application or the user needs to know the IDENTITY ...